Apparatus for centering media on a spindle

ABSTRACT

A media centering spindle assembly with a spindle body and a clutch drive assembly. The spindle body includes a centering mechanism such as a rack and pinion or centering slat. The centering mechanism is configured to center and retain a media roll, ribbon supply or the like along the spindle body and includes at least one spring tab. The spring tab is deflectable from an initial position to a second position below a surface of the spindle body to allow the mounting of the media roll or the like. The assembly may be further configured as rotatable about a longitudinal axis of the spindle body with the clutch drive assembly having a friction level adjustable by rotation of a clutch adjuster about the longitudinal axis of the spindle body.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from U.S. Provisional Application No. 60/521,481, filed May 4, 2004, entitled MEDIA CENTERING SPINDLE; the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1) Field of the Invention

The present invention relates to media support spindle assemblies. More specifically, the invention relates to a side loading media spindle with a centering mechanism for centering the media on the spindle.

2) Description of Related Art

Spindles are used to support media rolls, take-up rolls, and printer ribbon supplies in a wide range of machinery, for example label printers. Spindles supported at one end allow easy media exchange via side loading of media rolls from the unsupported end, onto the spindle. Where media of different widths are used in a center justified print system, the media is fixed in place along the spindle by a centering mechanism.

Prior side loading spindle centering mechanisms have used a rack and pinion assembly to slidably position opposing right and left guide arms along the spindle for centering of the media roll. The pinion gear was incorporated into the supported end, resulting in the rack extending beyond the spindle assembly when the widest media was inserted onto the spindle, requiring additional space allocation for the spindle assembly within the printer and limiting design options for the printer configuration, overall. The guide arm at the unsupported side required manual movement out of the media insertion path before media insertion and then a manual return to a media retaining position. Finally, the spindle was fixed in place and the media roll loosely hung around the spindle, making it unusable for applications where tension in the ribbon is required, such as printer ribbon supply and or take-up spindles.

BRIEF SUMMARY OF THE INVENTION

The present invention addresses the above needs and achieves other advantages by providing a spindle assembly for supporting a media supply, a take-up roll, a printer ribbon supply or the like within a hosting device such as a printer. The spindle assembly according to the present invention simplifies center justified media loading of a range of media roll widths, via a one step slide until a spring tab clicks into place.

In general, the spindle assembly includes a spindle body and a centering mechanism. The spindle body includes a first end, a second end, a cylindrical outer wall and a centering mechanism. The outer wall is configured to engage the media or ribbon supply and extends from the first end to the second end. The outer wall defines at least one tab slot. The centering mechanism is configured to center the media or ribbon supply between the first and second end of the spindle body. The centering mechanism includes at least two tabs for holding the media or ribbon supply onto the outer wall.

In one aspect of the invention, at least one of the tabs is a spring tab. In particular, each spring tab is adapted to have at least a first position and a second position. In the first position, the spring tab extends outwardly from the outer wall. And in the second position, the spring tab extends at least partially down into one of the tab slots. Each spring tab may have an outward sloped edge. The outward edge is configured so that a media or ribbon supply will deflect the spring tab into its second position as the media or ribbon supply is slid over the spring tab.

According to one embodiment of the present invention, the outer wall defines two tab slots and an interior. The centering mechanism includes a first rack, a second rack, and a pinion. The pinion is positioned within the interior such that the pinion engages both the first rack and the second rack. More specifically, the pinion may be positioned proximate to a midpoint of the spindle body. The first rack and the second rack are both substantially within the interior. The first rack has one tab extending through one of the tab slots. The second rack has one spring tab.

The spring tab of the second rack is deflectable from the first position to the second position. In the first position, the spring tab extends through a tab slot and extends radially outwardly from the outer wall. And in the second position, the spring tab is deflected down partially or completely through that tab slot. Also, the spring tab of the second rack may have a distal end facing the tab of the first rack. When the media or ribbon supply is slid over the spindle body, the media or ribbon supply deflects the spring tab from its first to its second position to allow the media or ribbon supply to pass over the spring tab. When the media or ribbon supply clears the spring tab, the spring tab returns to its first position and the media or ribbon supply is retained between the tab of the first rack and the distal end of the spring tab of the second rack.

The number of tabs and tab slots may vary between embodiments. For example purposes only and not as a limitation, the outer wall may define three tab slots and the first rack may have two tabs. Each tab of the first rack extends through a tab slot.

The spindle body may also include a biasing device for biasing the first rack and second rack towards a minimum extension position. For example the biasing device may be a spring coupled between either the first rack or the second rack and either the first end or second end of the spindle body.

In addition, the spindle body may be formed partially from a first spindle half and a second spindle half. The first spindle half is adapted to mate with the second spindle half. In particular, the first spindle half can include one or more hooks and the second spindle half can include an equal number of connecting slots. The hooks and connecting slots are configured to engage each other in order to mate the first spindle half and the second spindle half together. Furthermore the pinion of the centering mechanism may be supported between the first spindle half and the second spindle half.

The spindle body may further include a media spring clip coupled to the outer wall. For example, the media spring clip may be contained between the first spindle half and the second spindle half. The media spring clip projects radially from the outer wall to engage the media or ribbon supply.

In another embodiment of the present invention, the centering mechanism may have a centering slat. More specifically, according to this embodiment, the outer wall defines a channel and the centering mechanism includes a slat configured to slide along the channel. The channel partially overlies at least one tab slot. The slat includes two ends, each end having a tab. At least one of those tabs is a spring tab.

In yet another aspect of the present invention, the spindle assembly further includes a clutch drive assembly coupled to the spindle body. The clutch drive assembly may include a clutch gear rotatably coupled to the spindle body. The clutch gear may have a variable friction level. More specifically the clutch drive assembly may have a clutch adjuster configured to change the friction level when rotated.

The clutch drive assembly may also include a shaft for supporting the clutch gear and the clutch adjuster and a bearing located between the spindle body and the shaft for allowing the rotation of the spindle body without the rotation of the shaft.

The present invention has several advantages. A media centering spindle assembly according to the present invention simplifies center justified media loading of a range of media roll widths, via a one step slide until the spring tab springs back to an initial position. The spindle assembly does not require space to be set aside for rack extensions external to the spindle body, increasing design options overall and allowing integration with a mechanism that is easily adjustable by the operator to a desired drag or tension level in the media path. Also, the benefits of the invention are provided with a reduced total number of individual components, improving manufacturing efficiency and reducing overall cost.

BRIEF DESCRIPTION OF DRAWINGS

Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

FIG. 1 is an exploded isometric view of one embodiment of the spindle body of the present invention;

FIG. 2 is an exploded isometric view of one embodiment of the clutch drive assembly of the present invention;

FIG. 3 is an exploded isometric view of one embodiment of the media centering spindle assembly of the present invention;

FIG. 4 is an external isometric view of the media centering spindle assembly of FIG. 3;

FIG. 5 is a reverse angle external isometric view of the media spindle assembly of FIG. 4;

FIG. 6 is an end view of the media centering spindle assembly of FIG. 4, with a media roll mounted upon the spindle body;

FIG. 7 is a cross-sectional view of the media centering spindle assembly of FIG. 6, along line A-A;

FIG. 8 is a cross-sectional view of the media centering spindle assembly of FIG. 6, along line B-B;

FIG. 9 is an external side view of the spindle assembly of FIG. 6, with a wide media roll;

FIG. 10 is an external side view of the spindle assembly of FIG. 6, with a narrow media roll

FIG. 11 is a second embodiment of the present invention, wherein the tabs are at a maximum extension position;

FIG. 12 is the same embodiment as FIG. 11, wherein the tabs are in a minimum extension position;

FIG. 13 is a side view of the centering slat according to the embodiment illustrated in FIGS. 11 and 12.

DETAILED DESCRIPTION

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.

In general, the present invention includes a spindle assembly 10 for supporting a media roll 11. The spindle assembly 10 includes a spindle body 13 and a clutch drive assembly 60. The spindle body 13 is for holding the media roll 11. The clutch drive assembly 60 is for supporting and rotating the spindle body 13 and thus the media roll 11. It should be understood that although the spindle assembly 10 is described in the context of holding a media roll 11 a media roll 11 is only an example of the numerous applications for the present invention. For example purposes only and not as a limitation, the spindle assembly 10 may also support a take-up roll or a printer ribbon supply.

As best shown in FIGS. 1 and 3, the spindle body 13 is generally cylindrical in shape and extends distally from the clutch drive assembly 60. However, one in the art would appreciate that the spindle body 13 is configured to mate with the core of the media roll 23 and as such the spindle body 13 may take a variety of shapes, as well as having a variety of sizes, depending on the intended type of media or take-up roll 23 for the spindle assembly 10.

According to the illustrated embodiments, the spindle body 13 has a substantially cylindrical outer wall 14 and a centering mechanism 39. The outer wall 14 defines a body interior having a diameter and extends between a first end 15 and a second end 16. The first end 15 is supported by the clutch drive assembly 60. The second end 16 is unsupported and is the end from which the media roll 11 is loaded and unloaded onto the spindle body 13. The centering mechanism 39 includes at least two tabs 47 a, 47 b. As explained in more detail further below, the tabs 47 a, 47 b are configured to retain the media roll 11 on the spindle body 13.

The cylindrical outer wall 14 also defines a number of slots. As shown in FIGS. 1-3, the wall 14 defines three tab slots 17, 18, 19. In particular, one tab slot 18 extends from the unsupported end 16 less than half the length of the spindle body 13 toward the supported end 15. The two other tab slots 17, 19 are opposite each other and extend from the supported end 15 less than half the length of the spindle body 13 toward the unsupported end 16. One of the tabs slots 17 generally lines up with the tab slot 18 proximate to the unsupported end 16. However, the length and number of the slots 17, 18, 19 and the spatial relationship between them may vary. For example and as explained further below, the cylindrical wall 14 may define only one tab slot 18.

The interior diameter of the spindle body 13 may vary. In particular, the cylindrical wall 14 proximate to the supported end 15 may extend outwards relative to the rest of the body 13 providing a larger diameter near the supported end 15. Also, according to the illustrated embodiment, extending from the inner surface of the wall 14 near the larger diameter area of the body 13 is a bearing support 20. The bearing support 20 extends across the interior generally perpendicular to the length of the body 13. The support 20 defines a bearing surface 21 that is generally cylindrical and extends in a parallel fashion with the spindle body 13. The bearing surface 21 also may define a series of ridges. In the general area halfway between the two ends 15, 16 is a shaft support 25. The shaft support 25 extends across the interior of the body 13 and defines a shaft guide hole 26.

The spindle body 13 may be formed by a first spindle half 35 and a second spindle half 36, as shown in FIG. 1. The two halves 35, 36 when combined form the spindle body 13 described above. The two halves 35, 36 may be configured to snap together. For example purposes only and not as a limitation, the first spindle body half 35 may have a plurality of hooks 37 adapted for latching into corresponding slots 38 formed in the second spindle half 36. However one in the art would appreciate the numerous methods and structures that may be used to mate the first half 35 and second half 36 together. For example, the halves 35, 36 may be adhered together by an adhesive. The use of the halves 35, 36 facilitates the construction and assembly of the spindle assembly 10. For example, it provides easy access to the interior of the spindle body 13.

The spindle body 11 also includes a media spring clip 44 attached to the cylindrical wall 14. Although it may be attached to the wall 14 in a variety of methods, in the illustrated embodiments the media spring clip 44 is retained between the first spindle half 35 and the second spindle half 36. Alternatively, the media spring clip 44 may be adhered to the wall 14 with an adhesive or a fastener. The media spring clip 44 extends beyond the outer diameter of the spindle body 13 to removably retain a media roll 11 mounted upon the spindle body 13.

The centering mechanism 39 of the spindle body 11 is another aspect of the present invention. As stated above, the centering mechanism 39 is for retaining the media roll 11 on the spindle body 13. Moreover the centering mechanism 39 is configured to center the media roll 11 between the two ends 15, 16 of the spindle body 11. The centering mechanism 39 includes two or more tabs 47 a, 47 b. The tabs proximate to the supported end 15 are referred to herein as inward tabs 47 a. The tabs proximate to the unsupported end 16 are referred to herein as outward tabs 47 b. The inward and outward tabs 47 a, 47 b are coupled together so that the movement of the inward tabs 47 a causes an equal but opposite movement in the outward tabs 47 b. Similarly, a movement of the outward tabs 47 a causes an equal but opposite movement in the inward tabs 47 b. The inward tabs 47 a and the outward tabs 47 b are approximately equal distance to the midpoint between the ends of the spindle body 13.

In general, the outward tabs 47 b function as spring tabs as explained further below and may at times be referred to as such. The outward (or spring) tabs 47 b have an outward sloped edge facing the unsupported end 16 and a distal end 52 that is generally perpendicular to the length of the spindle body 13 and facing the inward tabs 47 a. Each outward tab 47 b overlies one of the tab slots 18 defined in the outer wall 14 and is configured to have at least two positions. In the first position, the outward tab 47 b extends generally perpendicular to and outwardly from the outer wall 14 and a tab slot 18. In the second position, the outward tab 47 b is extended into and below the tab slot 18 and partially inward of the outer wall 14. Each outward tab 47 b is biased to the first position and thus will move or spring back to the first position when possible.

When loading, the media roll 11 is slid along the spindle body 13 from the unsupported end 16 to the supported end 15, when the leading edge contacts an outward facing slope of a spring tab 47 b, the leading edge pushes the spring tab 47 b from its first position to its second position so that the media roll 11 can pass over the spring tab 47 b. When the leading edge of the media roll 11 contacts an inward tab 47 a, the inward tab 47 a slides along with the leading edge toward the supported edge 15 which causes the outward tab or tabs 47 b to move toward the unsupported edge 16. When the trailing edge of the media roll 11 passes the outward tab or tabs 47 b, each outward tab 47 b springs back to its first position and the media roll 11 is retained between the inward tab or tabs 47 a and the distal end 52 of each outward tab 47 b. When unloading, the outward tab or tabs 47 b are pushed down to their second positions by an operator or other outside force and the media roll 11 is slid over the outward tab or tabs 47 b and the rest of the spindle body 13.

According to the first embodiment shown in FIGS. 1 through 10, the centering mechanism 39 includes an inward rack 40, an outward rack 41, a pinion 42, and a biasing device 43. The inward rack 40 has an elongated portion 45 containing a row of teeth and a U-shaped tab portion 46 with a tab 47 a at each end of the “U.” The outward rack 41 has an elongated portion 50 containing a row of teeth and a spring tab 47 b. In particular, the spring tab 47 b is formed by a deflection loop 51. The deflection loop 51 extends from the elongated portion along a 270 degree path such that the distal end 52 of the loop 51 is extending back toward the elongated portion, as best seen in FIG. 1. The pinion 42 has a central gear portion and two ends 56, 57. The biasing device 43 may be a coil spring and the media spring 44 may be a leaf spring.

The racks 40, 41 are supported by rack guides 28 defined by the cylindrical wall 14. Also the racks 40, 41 may extend through rack openings defined by the bearing support 20 and shaft support 25. The inward rack 40 is configured so its teeth face inward and each tab 47 at each end of the “U” 46 is projecting through one of the tab slots 17, 19. Similarly, the outward rack 41 is configured so its teeth face inward and the spring tab 47 b is projecting through the tab slot 18 proximate to the unsupported end 16. The spring tab 47 b is biased to a first position such that it has an outward sloped edge facing the unsupported end 16 and its distal end 52, which is generally perpendicular to the length of the spindle body 13, is facing the supported end 15. The inward tabs 47 a of the inward rack and the spring or outward tab 47 b of the outward rack 41 are linked so the movement of one causes the movement of the other in an equal distance in the opposition direction. More specifically, the inward tabs 47 a and the outward tab 47 b are linked by the pinion 42. The ends 56, 57 of the pinion 42 are configured to rotatably engage pinion supports 30 defined by the outer wall 14 proximate to the shaft support 25. And the gear portion 55 of the pinion 42 is configured to engage the teeth of both racks 40, 41. The rotation of the pinion 42 causes the racks 40, 41 to slide along the rack guides 28. Therefore the movement of the inward tabs 47 a and thus the inward rack 40 causes the pinion 42 to rotate and move the outward rack 41 and thus the spring tab 47 b in the opposite direction. Similarly, the movement of the spring tab 47 b causes the movement of the inward tabs 47 a.

The racks 40, 41 and pinion 42 are biased into a minimum extension position between the inward tabs 47 a and the outward tab 47 b by the biasing device 43. The bias device 43 may be coupled between the unsupported end 16 of the spindle body 13 and the inward rack 40 as shown in FIG. 7. Alternatively, the bias spring 43 may be coupled between the unsupported end 16 of the spindle body 13 and the outward rack 41.

According to this embodiment, the media roll 11 is held in place on the spindle body 13 by the media spring 44, the tabs 47 a of the inward rack 40, and the spring tab 47 b of the outward rack 41. As stated above, the overall shape of the spindle body 13 is configured to mate with the core of the roll 11. The roll 11 is inserted and slid across the spindle body 13 from the unsupported end 16 to the supported end 15. When the leading edge of the core contacts the spring tab 47 b it engages the loop's sloped edge and deflects the spring tab 47 b down toward the wall 14 and partially through the tab slot 18 allowing the roll 11 to pass over the spring tab 47 b. When the leading edge contacts the inward tabs 47 a, the leading edge will push the inward tabs 47 a toward the supported end 15 along with the leading edge. Once the trailing edge passes the distal end 52 of the spring tab 47 b, which is moving in the opposite direction of the inward tabs 47 a, the spring tab 47 b will spring back. After the roll 11 clears the spring tab 47 b, the inward tabs 47 a and the distal end 52 of the spring tab 47 b hold the media roll 11 in place relative to the length of the spindle body 13. The media spring 44 exerts pressure onto the roll 11 creating a rotatable link between the spindle body 13 and the roll 11 so that the roll 11 rotates with the spindle body 13. To remove the roll 11, the spring tab 47 b is pushed down by an operator or other outside force to clear the core beyond the spring tab 47 b as the core is slid off the spindle body 13.

In a second embodiment of the present invention, the centering mechanism 39 includes a centering slat 115 shown in FIGS. 11 through 13. The centering slat 115 is an elongated member with two outer ends, an inward end 120 and an outward end 125. Also the centering slat 115 has an inward tab 47 a and an outward tab 47 b that extends generally perpendicular to the rest of the slat 115. The inward tab 47 a is at or proximate to the inward end 120. Similarly, the outward tab 47 b is at or proximate to the outward end 125. At least a portion of the slat 115 is configured to be flexible including at least one end 125. For example, the slat 115 may be made from a flexible plastic with a saw-tooth structure that allows the slat 115 to bend or flex to a significant degree.

According to this embodiment, the cylindrical wall 14 defines a channel 130 that extends within the outer wall 14 of the spindle body 13. In particular, the channel 130 extends from the supported end 15 to the unsupported end 16, through a semicircular (180° portion) defined at the unsupported end 16, and out of the semicircular portion toward the supported end 15, but not the full distance to the supported end, as shown in FIGS. 11 and 12. The path coincides with at least one tab slot 18 defined in the outer wall 14 that extends from the unsupported end 16 to approximately half the length to the supported end 15.

The centering slat 115 is configured to slide along the channel 130. The movement of one tab 47 a, 47 b causes the opposite and equal movement of the other tab 47 a, 47 b along the spindle body 13. The outward tab 47 b, i.e. the tab closest to the unsupported end 16, is part of the flexible portion of the centering slat 115 and overlies the tab slot 18 allowing the outward tab 47 b to be deflected toward and into the tab slot 18 and thus function as a spring tab. Furthermore, the outward tab 47 b has an outward sloped edge facing the unsupported end 16 and a distal end 52 that is generally perpendicular to the length of the spindle body 13 and facing the supported end 15. The channel 130 may have one or more partially covered areas to retain the centering slat 115 in the channel 130.

Similar to the rack and pinion mechanism, the centering slat 115 is biased in a minimum extension position. For example, a spring may be coupled to either end 120, 125 of the centering slat and to one of the ends 15, 16 of the spindle body 13 or another support 20, 25 in the interior.

According to this embodiment, the media roll 11 is held in place on the spindle body 13 by the media spring 44, and the inward tab 47 a and the outward tab 47 b of the centering slat 115. As stated above, the overall shape of the spindle body 13 is configured to mate with the core of the roll 11. The roll 11 is inserted and slid across the spindle body 13 from the unsupported end 16 to the supported end 15. When the leading edge of the core contacts the outward tab 47 b in a first position it engages the outward sloped edge and deflects the tab down toward the wall 14 and partially through the tab slot 18 to a second position allowing the roll 11 to pass over the outward tab 47 b. When the leading edge contacts the inward tab 47 a, the leading edge will push the inward tab 47 a and thus the centering slat 115 toward the supported end 15 along with the leading edge. Once the trailing edge passes the outward tab 47 b, which is moving in the opposite direction of the inward tab 47 a relative to the ends 15, 16 of the spindle body 13, the outward or spring tab 47 b springs back to the first position. After the roll 11 clears the outward tab 47 b, the inward tab 47 a and the outward tab 47 b hold the media roll 11 in place relative to the length of the spindle body 13. The media spring 44 exerts pressure onto the roll 11 creating a rotatable link between the spindle body 13 and the roll 11 so that the roll 11 rotates with the spindle body 13. To remove the roll 11, the outward tab 47 b is pushed down to clear the core beyond the outward tab 47 b as the core is slid off the spindle body 13.

In yet another aspect of the present invention and as best seen in FIG. 3, the spindle body 13 is coupled to the clutch drive assembly 60. The clutch drive assembly 60 may include a clutch face 65, a clutch face gear 70, a clutch spring 75, a spring cup 80, a clutch adjuster 85, a shaft extension 95, a shaft 100, a bearing 105, and a fastener 110.

In general, the clutch face 65 has a mating surface 66 and body surface 67 and defines a hollow cylindrical portion 68 projecting from the body surface 67. The cylindrical portion 68 is configured to engage the supported end 15 of the spindle body 13. The clutch face gear 70 has a spring surface 72 and mating surface 71 that is configured to mate with the mating surface 66 of the clutch face 65. The clutch face gear 70 also defines a hollow cylindrical portion 73 adapted to fit into and partially through the cylindrical portion 68 of the clutch face 65 and has a perimeter of gear teeth 74.

The clutch spring 75 may be a coil spring extending from the spring surface 72 of the clutch face gear 70 and the spring cup 80. The spring cup 80 includes a spring surface 81, an adjuster surface 82 and two extensions 83. The spring cup 80 also defines a central hole 84 with one or more protuberances. The spring surface 81 may define a recess configured to engage the clutch spring 75. The extensions 83 are adapted to engage the clutch adjuster 85.

The clutch adjuster 85 generally includes a cup portion 86 and a handle portion 87. The cup portion 86 has a substantially circular base that defines a central hole 90 and a profile extension 89. The profile extension 89 extends around and generally perpendicular from the base to a distal ridge 91. The distal ridge 91 defines one or more paired steps. The distance between a step and the base varies. More specifically, according to the illustrated embodiment, the distal ridge 91 defines three paired steps. Each paired step includes a support edge 92 with a detent 93 positioned at a predetermined distance from the base and a matching support edge 92 with a detent 93 at the same distance from the base on the opposite side of the ridge 91. The distal ridge 91 also defines gradual upward slopes between the support edges 92 from the step closest to the base to the furthest. The handle 87 is generally planar with the base and extends away from the central hole 84.

The shaft extension 95 may be an elongated cylindrical member configured to fit though the central holes 90, 84 of the clutch adjuster 85 and the spring cup 80, through the clutch spring 75, through the cylindrical hollow portions 73, 68 of the clutch face gear 70 and the clutch face 65, and into the bearing support 20 and shaft guide hole 26 of the spindle body 13. One end of the shaft extension 95 may be configured to attach to an end of a shaft 100 as shown in FIGS. 2 and 3. The other end of the shaft 100 opposite of the shaft extension 95 may have head portion 101. Similarly, the shaft 100 may also be configured to fit through some or all of the holes and structures that the shaft extension 95 fits through. The shaft 100 may also define one or more slots to engage the protuberances in the spring cup 80 for preventing the spring cup 80 from rotating about the shaft extension 95 or shaft 100.

The bearing 105 is configured to engage the shaft extension 95 and/or shaft 100. For example purposes only and not as a limitation, the bearing 105 may be a sleeve bearing configured to fit around the shaft extension 95 or the shaft 100 and held in place by stops on either the shaft extension 95 and/or shaft 100. In particular, the shaft extension 95 and shaft 100 extend through the central holes 90, 84, the clutch spring 75, and the cylindrical hollow portions 73, 68 into the spindle body 13 such that the bearing 105 engages the bearing surface 21 in the spindle body 13. When the spindle body 13 rotates the bearing 105 may partially rotate with the spindle body 13 while the shaft extension 95 remains stationary. One in the art would appreciate that the configuration of the shaft extension 95, shaft 100, and bearing 105 may vary within this invention. For example the shaft extension 95 and shaft 100 may be an integrated component. Or the bearing 105 may be affixed to the spindle body 13 rather than to the shaft extension 95 or shaft 100.

As shown in FIGS. 6 through 8, the head portion 101 of the shaft 100 may define a mating hole for a fastener 110 for fastening the spindle assembly 10 to a hosting device. The head portion 101 may also function as a stop for lining up the shaft 100 and thus the shaft extension 95 and bearing 105 to the rest of the clutch drive assembly 60 and the spindle body 13.

As stated above, the clutch spring 75 engages both the spring surface 72 of the clutch face gear 70 and the spring surface 81 of the spring cup 80. More specifically, the clutch spring 75 biases the clutch face gear 70 into the clutch face 65 and biases the spring cup 80 into the clutch adjuster 85. The bias may be adjusted by adjusting the distance between the spring surfaces 72, 81. This distance is adjusted with the spring cup 80 and the clutch adjuster 85. By rotating the handle 87 of the clutch adjuster 85 around the shaft 100, the extensions 83 of the spring cup 80, which can not rotate itself due to the engagement of the protuberances in the central hole of the cup 80 and the slots in the shaft 100, slide along the distal ridge 91 of the clutch adjuster 85. The distance of the spring cup 80 to the clutch face gear 70 changes as the spring cup 80 moves from step to step on the distal ridge 91. When the distance decreases the bias increases and likewise when the distance increases the bias decreases.

The variable bias provides the spindle assembly 10 with a variable operating tension for rotating the media roll 11. In particular, a drive mechanism of the hosting device such as a label printer engages the clutch face gear 70 to drive the spindle body 13 via the friction between the mating surfaces 66, 71 of the clutch face gear 70 and the clutch face 65. The level of friction is selectable by the operator via rotation of the clutch adjuster 85 to adjust the spring bias. The desired friction level may be selected, for example, depending upon the width of the media roll 11 used, thereby maintaining an optimal tension in the printer ribbon and or media paths. Similarly, the clutch drive assembly 60 may be implemented on a media spindle that is undriven, for example on a supply rather than take-up spindle, by omitting the drive mechanism linkage.

The present invention has several advantages. A media centering spindle assembly 10 according to the invention simplifies center justified media loading of a range of media roll widths, via a one step slide until the spring tab 47 b springs back to an initial position. The spindle assembly 10 does not require space to be set aside for rack extensions external to the spindle body 13, increasing design options overall and allowing integration with a mechanism that is easily adjustable by the operator to a desired drag and or tension level in the media path. Also, the benefits of the invention are provided with a reduced total number of separate components, improving manufacturing efficiency and reducing overall cost.

Where in the foregoing description reference has been made to ratios, integers or components having known equivalents then such equivalents are herein incorporated as if individually set forth. While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus, methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of the applicant's general inventive concept. Further, it is to be appreciated that improvements and/or modifications may be made thereto without departing from the scope or spirit of the present invention as defined by the following claims. 

1. A spindle assembly for supporting a media or ribbon supply in a hosting device, said spindle assembly comprising: a spindle body including a first end, a second end, an outer wall and a centering mechanism, the outer wall is configured to engage the media or ribbon supply, extends from the first end to the second end, and defines at least one tab slot, the centering mechanism is configured to center the media or ribbon supply between the first and second end, and includes at least two tabs configured to abut and hold ends of the media or ribbon supply, wherein at least one tab is a spring tab having a first position and a second position, in the first position the spring tab extends outwardly from the outer wall and in second position the spring tab extends at least partially into a tab slot.
 2. The spindle assembly according to claim 1, wherein the spring tab has a sloped outward edge, whereby a media or ribbon supply slid over the spindle body will deflect the spring tab from the first position to the second position.
 3. The spindle assembly according to claim 2, wherein the outer wall defines at least two tabs slots and an interior and the centering mechanism further includes a first rack, a second rack, and a pinion, said pinion being within the interior such that the pinion engages both the first rack and the second rack, said first rack being substantially within the interior and having at least one tab extending through a tab slot, and the second rack being substantially within the interior and having the at least one spring tab, the spring tab being deflectable from the first position to a second position.
 4. The spindle assembly according to claim 3, wherein the outer wall defines three tab slots and the first rack includes two tabs, each tab extending through a tab slot.
 5. The spindle assembly according to claim 3, wherein the pinion is located proximate a midpoint of the spindle body.
 6. The spindle assembly according to claim 3, wherein the spring tab of the second rack has a distal end facing a tab of the first rack, whereby when the media roll is slid across the spring tab and the spring tab returns to the first position, the media or ribbon supply is retained between at least one tab of the first rack and the distal end of the spring tab of the second rack.
 7. The spindle assembly according to claim 3, wherein said spindle body further includes a biasing device for biasing the first rack and second rack towards a minimum extension position.
 8. The spindle assembly according to claim 7, wherein the biasing device is a spring coupled between either the first rack or the second rack and either the first end or second end of the spindle body.
 9. The spindle assembly according to claim 3, wherein the spindle body is formed partially from a first spindle half and second spindle half, the first spindle half is adapted to mate with the second spindle half.
 10. The spindle assembly according to claim 9, wherein the pinion is supported between the first spindle half and the second spindle half.
 11. The spindle assembly according to claim 9, wherein the first spindle half includes at least one hook and the second spindle half includes at least one connecting slot, each hook is configured to engage a corresponding connecting slot of the second spindle half to mate the first spindle half and the second spindle half together.
 12. The spindle assembly according to claim 2, wherein the spindle body further comprises a media spring clip coupled to the outer wall and projecting radially from the outer wall.
 13. The spindle assembly according to claim 2, wherein the outer wall further defines a channel and the centering mechanism further includes a slat configured to slide along the channel, said channel partially overlies at least one tab slot and said slat includes two ends, each end having a tab, wherein one of the tabs is a spring tab.
 14. The spindle assembly according to claim 13, wherein the centering mechanism further include a biasing device for biasing the slat towards a minimum extension position.
 15. The spindle assembly according to claim 14, wherein the biasing device is a spring.
 16. The spindle assembly according to claim 1, further comprising a clutch drive assembly coupled to the spindle body.
 17. The spindle assembly according to claim 16, wherein the clutch drive assembly includes a clutch gear rotatably coupled to the spindle body.
 18. The spindle assembly according to claim 17, wherein the clutch gear has a variable clutch friction level.
 19. The spindle assembly according to claim 18, wherein the clutch drive assembly further includes a clutch adjuster for adjusting the variable friction level of the clutch drive assembly.
 20. The spindle assembly according to claim 19, wherein the rotation of the clutch adjuster controls the variable friction level of the clutch
 21. The spindle assembly according to claim 20, wherein the clutch drive assembly further includes a shaft for supporting the clutch gear and the clutch adjuster.
 22. The spindle assembly according to claim 21, wherein the clutch drive assembly further includes a bearing located between the spindle body and the shaft for allowing the rotation of the spindle body without the rotation of the shaft.
 23. A spindle assembly for supporting a media or ribbon supply in a hosting device, said spindle assembly comprising: a spindle body including a first end, a second end, an outer wall and a centering mechanism, wherein the outer wall is configured to engage the media or ribbon supply, extends from the first end to the second end, and defines at least one tab slot and a channel positioned in communication with the tab slot, said channel having at least one bend reversing the direction of the channel, and wherein the centering mechanism includes a slat configured to slide along the channel and at least two tabs with one of the tabs positioned on an end of the slat and the other of the tabs positioned on an opposite end of the slat, wherein the tabs are configured to abut and hold ends of the media or ribbon supply.
 24. A method of centering a media roll or ribbon supply onto a spindle body, comprising: inserting the media roll or ribbon supply onto an unsupported end of the spindle body; sliding the media roll or ribbon supply to a first tab: deflecting the first tab from a first position to a second position such that the media roll or ribbon supply can slide over the first tab; sliding the media roll or ribbon supply to a second tab; engaging the second tab with the media roll or ribbon supply and sliding the second tab along with the media roll or ribbon supply, until the media roll or ribbon supply clears the first tab; returning the first tab to the first position; and holding the media roll or ribbon supply between the first tab and the second tab. 